$ git clone -n https://src.fedoraproject.org/rpms/vdr.git /var/lib/mock/f40-build-794879-139800/root/chroot_tmpdir/scmroot/vdr
Cloning into '/var/lib/mock/f40-build-794879-139800/root/chroot_tmpdir/scmroot/vdr'...
$ git fetch origin 50353a360970d228cf158709847b66cd0a141046:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/vdr
 * [new ref]         50353a360970d228cf158709847b66cd0a141046 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 50353a3 Update to 2.6.6